I've been taking a daily supplement of 400 IUs of vitamin E. I recently bought a bottle of 1000 IUs, and a friend told me that that's too much to take, and could even be bad for me. Is that true?

Dear Reader,

It’s no wonder you’re concerned about getting enough of this vitamin — some research has suggested that this antioxidant may prevent and/or treat conditions such as coronary heart disease, some cancers, and macular degeneration. However, as with other vitamins, nutrients, and minerals, it’s often best to get your vitamin E by eating a varied and healthy diet rather than using supplements. One exception to this recommendation is if your health care provider specifically recommends otherwise (more on that in bit). You ask whether taking a higher dose of vitamin E is too much — there has been some research to suggest that, in this case, more may not be better for your health. It’s best to consult with a health care provider to determine your specific vitamin E needs.

First thing’s first: How much vitamin E is recommended daily? The U.S. Recommended Dietary Allowance (RDA) for vitamin E in individuals 14 years or older is 22.5 IU (15mg). If you’re a breastfeeding woman, that recommendation increases to 28.5 IU (19mg). There is no need to exceed the RDA level of intake unless you have been diagnosed with a vitamin E deficiency or a condition that would put you at risk for a deficiency (e.g., those with Crohn’s disease, cystic fibrosis, a rare inherited condition called abetalipoproteinemia, and very low weight, premature infants may all be at risk for a deficiency). With those numbers in mind, taking 1000 IU, or even 400 IU, of vitamin E daily over the long-term can have the potential to do some damage to your body — not to mention your wallet.

If you’ve just started taking vitamin E supplements, you don't need to worry just yet; it doesn’t appear to be harmful in large doses of up to 1000 IU per day over a short period of time. However, one study has shown that taking supplements of 400 IU daily over the long-term is associated with an increased risk of mortality (from all causes). At the same large daily dose, another study found an increased risk of prostate cancer in adult men. Research findings overall, however, have not determined a clear association between large doses of vitamin E and adverse health effects. Conflating factors such as study participants with chronic diseases or research in populations with higher rates of nutritional deficiencies may make it difficult to tease out a true cause and effect from the results. It’s also been noted that vitamin E can interact with certain medications. If you’re taking anticoagulant or antiplatelet medications, being treated with a combination of simvastatin and niacin, or undergoing chemotherapy or radiotherapy, taking a vitamin E supplement is not advised.

How might you get the vitamin E you want without taking a pill? There are plenty of food sources rich in vitamin E. And some good news: While there is a potential for health risks with large-dose vitamin E supplements, this is typically not so with food sources. It might be time to find your favorite:

Almonds, peanuts, hazelnuts (filberts), sunflower seeds

Wheat germ, cereal grains

Leafy greens, such as turnip greens, broccoli, and spinach

Kiwifruit, mango, and tomato

Sunflower and safflower oils

Lastly, it’s good to be aware that the amount of vitamin E in each pill can vary greatly because the Food and Drug Administration (FDA) does not regulate nutritional supplements. That is, your 400 IU supplement may contain much more or much less vitamin E than what is listed on the label. Bottom line — if you’re curious to know whether a vitamin E supplement is a healthy choice for you, it’s wise to speak with your health care provider. In the meantime, don’t be shy about grabbing a leafy green salad with almonds and a little sunflower oil!

For more information or to make an appointment, check out these recommended resources: